Interest is money the bank pays you for letting them use your deposits
When you put money in a savings account, the bank lends that money to other customers through mortgages, car loans, and business lines of credit. In exchange for the use of your money, the bank pays you interest — a percentage of your balance, calculated and added to your account on a schedule the bank sets. The interest rate varies by bank, by account type, and by how much money you have on deposit.
The bank does not pay you interest out of generosity. It is a transaction: you provide capital, the bank uses it to make loans at higher rates, and you receive a cut. The difference between what the bank pays you and what it charges borrowers is the bank's profit. This is why interest rates on savings accounts are always lower than interest rates on loans.
Interest is separate from your principal — the original amount you deposited. When interest is added to your account, it becomes part of your new balance, and future interest is calculated on that larger amount. This is called compounding, and it is the reason your money grows faster the longer it sits in the account.
Key Takeaways
- Banks pay interest on savings accounts because they use your deposits to make loans to other customers at higher rates.
- Interest rates vary by bank and account type, and higher balances sometimes earn higher rates through tiered structures.
- Interest is usually compounded daily or monthly, meaning interest earned gets added to your balance and earns interest itself.
- The annual percentage yield (APY) tells you the real rate you will earn over a year, including the effect of compounding.
How the interest rate is set and what it depends on
Banks set their own interest rates based on the federal funds rate — the rate the Federal Reserve charges banks to borrow from each other overnight. When the Fed raises its rate, banks typically raise the rates they pay on savings accounts. When the Fed lowers its rate, savings rates fall. This is why your savings account rate changes over time, even if you do nothing.
Competition between banks also drives rates. Online banks, which have lower overhead costs than brick-and-mortar branches, often pay higher interest rates on savings accounts than traditional banks. If you shop around, you may find rates that differ by 4 or 5 times from one bank to another, even on the same day.
Some banks offer tiered rates, meaning the interest rate increases as your balance grows. A bank might pay 0.01% on balances under $10,000 and 0.05% on balances above $100,000. Read the account terms carefully to see whether your rate will change if your balance crosses a threshold.
Annual Percentage Yield (APY) versus interest rate
The interest rate is the percentage the bank pays on your balance. The Annual Percentage Yield (APY) is the real return you will earn over one year, including the effect of compounding. APY is always equal to or higher than the stated interest rate, because it accounts for the fact that interest earned gets added to your balance and earns interest itself.
Banks are required by federal law to disclose the APY prominently when you open an account or compare accounts online. Always look at the APY, not the interest rate alone, because it shows you the actual money you will earn. If one bank advertises a 4.50% interest rate compounded daily and another advertises a 4.50% APY, the first bank is being less transparent — the APY would be slightly higher than 4.50%.
The difference between interest rate and APY is small on most savings accounts, but it matters over time. On a $10,000 balance, the difference between a 4.00% APY and a 4.50% APY is about $50 per year.
How often interest is compounded and paid
Banks compound interest on different schedules. Some compound daily, some weekly, some monthly, and some quarterly. Daily compounding is most common on high-yield savings accounts and means the bank calculates interest on your balance every single day, adds that day's interest to your account, and then calculates the next day's interest on the new, larger balance.
The frequency of compounding matters because more frequent compounding means your interest earns interest more often. Over a year, daily compounding will earn you slightly more than monthly compounding at the same stated rate. The difference is small on typical balances, but it adds up over years.
Interest is usually credited to your account monthly, though some banks credit it daily or quarterly. Crediting means the bank actually deposits the interest into your account so you can see it and withdraw it. Until interest is credited, it is not yet part of your balance and does not earn interest itself. Check your account statement or the bank's website to see when interest was last credited to your account.
What happens to interest if you withdraw money
If you withdraw money from your savings account, the interest you earn going forward is calculated on the smaller balance. If you had $10,000 earning 4.50% APY and withdrew $5,000, your new balance of $5,000 will earn interest at the same 4.50% rate, but the dollar amount of interest will be half as much.
Interest that has already been credited to your account is yours to keep. If the bank paid you $37.50 in interest last month and you withdraw it, that money is gone, but you have not lost anything — you earned it and chose to spend it. Interest that has not yet been credited is still being calculated and will be added on the next crediting date, regardless of whether you withdraw other money.
Some savings accounts have withdrawal limits or penalties for frequent withdrawals. These rules are separate from interest calculations, but they can affect how much you actually earn. If you withdraw money and trigger a penalty fee, that fee reduces your net interest earnings. Read the account terms to understand any withdrawal restrictions before you open the account.
How to compare interest rates between banks
To compare savings accounts fairly, look up the APY for each account you are considering and note the minimum balance required to earn that rate. Some banks advertise a high APY but only pay it on balances above $25,000 or $100,000. If you have $5,000, that advertised rate may not apply to you.
Use a savings rate comparison website or check the websites of banks you already use and banks you are considering. Write down the APY, the compounding frequency, the minimum balance requirement, and any fees that apply. Multiply your expected balance by the APY to estimate how much interest you will earn in a year, then subtract any monthly fees. The account with the highest net earnings is usually the best choice.
Remember that interest rates change. A bank offering 4.50% today might drop to 4.00% in three months if the Federal Reserve lowers rates. If you find a high rate, it is worth moving your money to that bank, but do not expect the rate to stay the same forever. Check your rate once or twice a year and move your money if a better option appears.
Interest earned on savings accounts and taxes
Interest you earn on a savings account is taxable income. At the end of each year, your bank will send you a Form 1099-INT showing how much interest you earned. You must report this amount on your federal tax return, even if the amount is small.
The tax you owe on interest depends on your overall income and tax bracket. If you earned $50 in interest and you are in the 22% tax bracket, you will owe about $11 in federal income tax on that interest. Some states also tax interest income. Check your state's tax rules or speak with a tax professional if you are unsure.
This is why the real return on a savings account is lower than the APY. If you earn 4.50% APY on $10,000 and owe 22% in taxes on that interest, your after-tax return is closer to 3.5%. This does not change how you should save — you still want the highest APY available — but it is worth understanding that some of your interest earnings will go to taxes.
Frequently Asked Questions
Can I lose money in a savings account because of interest rates?
No. Interest is money added to your account, never subtracted. Your balance can only stay the same or grow. However, if inflation is higher than your interest rate, your money loses purchasing power — you can buy less with it even though the account balance is higher. This is why comparing your APY to the inflation rate matters for long-term savings.
What is the difference between a savings account and a money market account?
Money market accounts often pay higher interest rates than savings accounts, but they usually require a larger minimum balance and limit how many withdrawals you can make per month. Both are FDIC-insured up to $250,000. Choose based on whether you need frequent access to your money or can leave it untouched for longer periods.
Why do online banks pay more interest than traditional banks?
Online banks have lower costs because they do not operate physical branches. They pass some of those savings to customers through higher interest rates. The trade-off is that you cannot walk into a branch to deposit cash or speak to someone in person. Most online banks offer phone and email support instead.
Does interest compound if I do not touch my account?
Yes. Compounding happens automatically. You do not have to do anything. As long as your money stays in the account, interest is calculated and added on the bank's schedule, and future interest is calculated on the new balance. This is one reason leaving money in a savings account for years can result in significant growth.
What happens to my interest if the bank fails?
Your deposits and any interest earned are protected by the FDIC (Federal Deposit Insurance Corporation) up to $250,000 per account holder per bank. If a bank fails, the FDIC pays you back, including all interest that had been credited to your account. Interest that had not yet been credited is typically paid as well, though the exact rules depend on the timing of the failure.